Dust guard for pulverizers and other devices



March 26, 1940.

G. FRASER DUST GUARD FOR PULVERIZERS AND OTHER DEVICES Filed July 20, 1935 2 Sheets-Sheet 1 |NVENTOR= March 26, 1940. G. H. FRASER DUST GUARD FOR PULVERIZERS AND-OTHER DEVICES Filqd July 20, 1935 2 Sheets-Sheet 2 INVENTOR:

Patented Mar; 26, 1940 v "rear OFFICE I nps'r GUARD FOR PULYVERIZERS AN OTHER DEVICES I This application is a continuationin part of my application Serial No; 580,628, filed December 12, 1931, now Patent No. 2,040,841, issued May 19,1936.

g This invention relates to dust guards for the shafts of the type of pulverizers having a crushing die member having an inner annular crushing face, a rotatable crushingroll member having a, a

Such dust guards have comprised an inner dust chamber around the roll shaft, a dust collar spaced therein, an outer radially slidable dust plate, radially slidable grease washers between it and the bearing, and arotatable collar carrying the plate :and washers from the shaft and moving them radially 'therewithto resist leakage i wall through which the ring B may be inserted around the shaft during its radial movement.

The purposes of my invention are to improve such leakage prevention provisions, and to provide improved sealing means'for a shaft opening for aradially movable or swingable shaft.

For acccmplishing'these purposes I provide,

various features I of improvement, all of which will be more fully hereinafter set forth, in their preferred forms, as shown in the accompanying thereof, the view being cut approximately on the planes of thelinesZ-Z in Fig. l, and showing the upper and front rolls in plan, and the rear roll in partly radial section, and the upper bearing in horizontal section; 1

3 is an enlarged fragmentary vertical axial section of one of the upper bearings and itsdust guardand roll, and

Fig. 4 is a side elevation dust guards, partly broken away to show itsdust chamber and one of its slidable. plates therein, and the ch'eek'pieceenclosing it.

Referring to the drawings let A indicate the casingof a ring and roll pulverizer, B a crushing die therein, havingan inner annular crushing aims to improve such dust of one of the lower face I), C an upperrolLCl a front roll, and C2 a rear roll, each having a peripheral crushing face G- within the inner face I), D a supply inlet, E a dischargeoutlet, F a drive pulley, H the shafts, I their bearings, J their bearing frames,

N dust guards around the shafts H, L springs for pressing the rolls toward the die, M adjusting screws for the, springs, W radiallymcvable or swingable yokes carrying the bearing members J from the casing A, X inner check springs between the casing. A and the yokes W, Z the outer check springs against the yokes W, Y swingable bolts for carrying and adjusting the springs Z, ,O the crushing chamber,v and P the discharge chamber. j

These parts may be the usual conventional features of any knownltype of pulverizer, for crushing material between the crushing faces with a yieldable crushing pressure.

The die B is usually a ring, and that shown is of the typewhich is rotatably and movably carried by the up'perroll C, rotation of which tractionally rotates the die, which tractionally I and removed. ;A ring cover A closes the side of the casing A andcarries a cheek piece Z at the side of the ring. The cover A has a roll aperture at the side of each roll, through which a roll may be inserted and removed. Each roll aperture is coveredby a dust guard N, which has a shaft slot qthroughwhich its shaft Hextends. Each shaft H is radially movable, and is usually carried by a'movable bearing I whichusually has a semispherical periphery v movably mounted in a semi-spherical socket y in the bearing member J, which latter is usually radially movable or swingable, and axially sustains the roll and thereby axially positions the ring. The dustguard N usually comprises a singlechambered casting which has an inner wall a near the side of the roll, and an outer wall 22, which walls have slots q around theshaft and encloses a dust chamber to and a spaced dust collar b spaced therein. A dust plateau, and greasewash ers i ands, are usually radially slidable between the dust guard N and the bearing member J, and are usually carried from the shaft H by a collar rand pressed apart by springs m, for resisting leakage toward or from the hearing I.

. When such pulverizers have three rolls mounti ed on radially movable horizontal shafts the upper shaft moves vertically and the lower shafts move at angles of approximately. 30 degrees from shown the shafts swing from the centres on which these frames are hinged respectively, so that radial movement of the shaft is in an are shaped path co-axial with the centre from which its frame swings, and in the case of the lower shafts extending approximately at an angle of 30 degrees from the horizontal.

The type of pulverizer shown has a conical, outwardly fiared, rotatable interceptor face 0 between the dust guard N and the crushing faces, which is extended across and radially outwardly of the crushing faces and around and radially outwardly of the dust guard, at the side of the crushing faces, to divergently deflect around and away from the latter crushed material discharged therefrom, and the side of the die has a reciprocal conical, outwardly flared, crushed material discharge face a, extended radially outwardly around its inner crushing face and around'and outwardly of the dust guard, to divergently discharge crushed material between the conical faces and divergently around and away from the dust guard. The faces 0 and a are preferably of like conicity and tractionally engageable for transmitting rotation from one to the other, and for the upper roll are preferably in axially and radially compressive wedging engagement, and thereby operable to axially resist approach of the die toward the dust guard, for defining the space therebetween, and, when desired, to radially space the crushing faces, for limiting the fineness of crushing, as shown in Fig. 3.

For the lower rolls the conical faces 0 are preferably spaced axially from the conical faces a, a permit normal axial movement of the ring, and are operable to divergently discharge the crushed material around and away from the dust guard'through the space between these faces, and to resist abnormal axial movement of the ring by tractionally engaging and axially checking such abnormal movement a predetermined distance from the dust guard, as shown in Fig. 2, in which the conical faces c for the lower roll C2 are shown as spaced from the sides of the ring and as formed on collars d, which are removably bolted to the sides of the lower rolls, and one of which positions its roll on its shaft H by clamping it against a shoulder e thereon. The conical faces 0 for the lower rolls are extended from a radial distance inwardly of their crushing faces, to provide the desired divergent discharge space between the conical faces, and to permit wear of the crushing faces without molestation from the conical faces.

In pulverizers of the type shown the ends of each shaft H extend beyond the sides of the casing A, and are carried by the ends of theyokes W, respectively, which are U-shaped castings swingable about the axis of a hinged connection with the casing, for moving the shafts in parallelism with said axis, and each spring L is in operative relation to and constitutes a means for radially outwardly moving the adjacent yoke W and the shaft carried by the latter, and each spring Z is in operative relation to and constitutes a means for radially inwardly moving the adjacent yoke W and the shaft H carried by the latter, and when a yoke W is hinged as shown its springs L and Z constitute a means for radially the thickness of material being crushed on the inner face of the ring B.

In such constructions each dust plate a has been non-rotative and has been sustained by the shaft H which has been revoluble in a shaft hole in the plate, and radial movement of which has radially moved the plate with and in response to inward and outward movement of its shaft.

In such constructions the weight of each dust plate 2 has been sustained by the shaft H which has revolved in the shaft hole in the plate and during radial movement has contacted with such hole for radially moving the plate with the shaft.

Rotation of a shaft H in a plate 2 has tended to enlarge the shaft hole in the plate, and the weight of the plate on the shaft has tended to elongate said hole and impair the sealing efficiency of the plate.

Such plates have heretofore been circumferentially immovable relatively to the shaft they surrounded and to the wall on which they slid during radial movements of the shaft, and have moved in parallelism with such movement, which involved continuousqcontactive engagement between identical portions of a plate a and an adjacent wall as, and permitted particles entering therebetween to wear radial grooves in such identical portions, which soon impaired their sealing effectiveness and thus shorten the effective wear life of the plate.

Such radialmoveme-nt of a plate a in parallelism with radial mo-vement of its shaft H endangered entry of particles between a plate a and the adjacent wall as, and resisted dislodgment of such particles from therebetween.

Objects of my present invention are to improve the sealing efficiency and increase the effective wear life of a dust plate around a revoluble shaft, and for accomplishing this one feature of my present invention'makes such a plate movable circumferentially of its shaft, and provides circumferential movement means in operative relation to it and constructed to move it circumferentially of said shaft.

When such a plate is around and radially movable with a revoluble and radially movable shaft having means for radially moving it during its rotation, one feature of my invention aims to make such a plate rollable during and in response to radial movement of such shaft as the latter rotates within itsshaft hole, for rollably resisting leakage past the plate and for rollably dislodging particles between the latter and .a wall with which it is in contactive engagement, and for circumferentially distributing said engagement over circmnferentially successive portions of the plate,.for increasing the. sealing efficiency and effective wear life of the latter, and according to one feature of my invention I preferably accomplish this by making such a plate circular or with a peripheral portion co-axial with said shaft, and by providing'tracl; means in operative relation to and rollably engaged by said portion, in such manner that the plate may roll on the track means and may be sustained and positioned thereby relatively to said shaft during and coincidently with radial movement of the latter, which plate and track means preferably have interengageable rotation resistance means, for resisting rotationof the plate with revolution of its shaft, and enforcement means for enforcing circumferential movement of the plate relatively to its shaft during said rollable movement of the plate, for accomplishing which I preferably make the track d .apertured andthe' plate 2 with peripheral teethc entered within said apertures and circumferentially resisting rotation of the plate with revolution of itsshaft while permitting the plate to roll on the track during radial movement of the shaft, and enforcing such roll- When such a plate is around and radially swingable with a radially swingable revoluble shaft having means for radially swinging it in an arc-shaped path co-axial with an axis about which said shaft is swingable, one feature'of my invention aims to; rollably sustain andposition said plate relatively to its shaft throughout said I swingable movement of the latter, and according to one feature of my invention preferably accomplishes this by making said track arc-shaped and co-axial with said axis and parallel with and extended throughout the circumferential length of said path, and bymaking the peripheral portion of said plate co-axial with said shaft and in rollable operative relation to and sustained by said track throughout said swingable movement.

According to one feature of improvement I'provide an open sided cup shaped roll cover y for the dust. guard N, the flanged edge of which axially removably engages the outer side of the ring cover A, and the circular cup shaped portion of which has an open outer side carrying an axially inwardly extended wall which projects within and extends circumferentially with its roll aperture, and has an inner wall a? inwardly of and closing the opening andadjacentthe side i of the roll, and has a slot q around the shaft H, and a dust outlet f below the shaft, and. I pro! vide within the cup shaped cover 1/ and axially removable radially slidable dust plate 2 around,

the dust plates 2 are eXpansively pressed from each other and againstthe inner and. outer walls of the dust chamber respectively, by a U shaped spring a and a coil spring h. When arotary collar 1) is used with these plates they are sufficiently spaced to clear it, and their expansion springs are spaced from itsperiphery sufficiently to permit its rotation without molesting them.

According to another feature of improvement the dust guard N preferably comprises'two' axially v separable and separably axially removable parts y and '0, which enclose the dust chamber 20 and the dust plates 2, access to which may be I had by axially removing the outer part 11 without removing the inner part y, or both parts, and,

the plates a'mayfbe axially removed together as an assembly. 2 I

According to another feature of improvement the, dust plates a are reliable and rollably movable during their radial movement, and are prevented from rotating with the shaft around which they are mounted, preferably by carrying their weight rollably and movably from the dust guard N so that they can roll thereon asv theymove relativelylthereto and will be guided and carried thereby, for which I preferably make each with a circular periphery or edge co-axial with its grease washers 2' for and preferably in rollable operative relation tothe 2 respectively and on which each may roll. The supporter d is preferably a track extended in the direction of radial movement of the-dust plates, and are shaped whenthe members J carryingthe shafts H are swingable as shown, to permit which the slots q are clearance slots. The track d preferably has apertur sthrough' which dustmay fall to the dust outlet 1, and

has teeth 0' in engagementwith these apertures, for resisting rotation of a plates during its radial movement.

Preferably the cheek piece Z, which is usually the circular periphery of each plate 2 preferably} carriedby. the ring cover A and projects there from through the ringaperture to near the side of the die B, is formed on its'inner periphery with inward projections m at each side'of a recess shaped roll cover 3 and thereby resists passage V of crushed material againstthis portion and prevents the die from striking it. The recess 0 is large enough to permit axial removal through it of the conical interceptor face 0' at the side of the adjacent roll, and atits sides the cheek piece Z is extended, from outwardly to inwardly of t the conical discharge face a of the die, for receiving crushed material discharged therefrom and conducting it across the cheek piece at each sideof the roll instead of permitting it to fall on the dust guard. i

Preferably the outer sideof the cheek'piece is formed below each lower dust guardwitha downward dust outlet n under the outlet, 1" from the lower dust chamber for receiving dust therefrom and precipitating it past the outer side of the cheek piece. I

In the construction shown I preferably provide for radially moving the outer plate 12 and the and s Iwithout tilting them, preferably by a spherical connection between them and the, collar r, for which I preferably provide a spherical connection p2 between the collar 1* and the grease washers z ands, and anarc shaped connection it between the washer s and the plate p so that these may be moved radially f without tilting during oscillation of theshaft.

For closing the ends of the bearing member J,

I preferably form its ends with are shaped faces g, and close the inner end by the grease washer z and its outerend by 'a grease washer h, each of which hasflan are shaped face 7' slidab'ly fitting against the adjacent face 9. The collar r holds the washer 2' against the inner end of the bearing member, and a collar lholds the washerh against the outer end thereof; The collar! is preferably covered byjan inner cap tf spaced within an eccentric outer cap go, between which an are shaped cover sslides to close the space 1 around the outer end of the shaft as it oscillates.

Springs is collars. v

p In the constiuctionwsholwn I;- resist leakage between the shaft Hand the bearing member ,J by providing a radially expansive and contracpreferably press the cap t"t0walfd the 'tive washern in the space between these, which is operable to expansively and contractively close this space during oscillation between the shaft and the bearing member. This preferably con sists of a cup shaped leather washer n enclosing the expansively and contractively coiled end of an axially compressive spring 0, which radially presses the flanges of thecup washer toward 20. c which encircles the outer portion of the cup" the bearing member and the shaft, and axially presses the cup washer toward the adjacent grease washer, and thereby resists leakage toward or from the bearing I and permits retention of lubricant within the bearing member J.

The construction shown provides for axially positioning the conical interceptor face 0 and the conical discharge face a positively in both directions relatively to the dust guard N by the hearing I, for which I preferably provide the inner periphery of the bearing I with an are shaped keyway (Z2, and the periphery of the shaft H with a reciprocal are shaped keyseat c2, and provide a concavo-convex key it which is rockable into engagement with the keyseat and keyway,

and thereby is axially resistant in both directions. The arcs of the keyseat and keyway and key are concentric and adapted to permit the ke to clear thebearing as it rocks out of engagement, and its accidental disengagement is preferably resisted by a spring ring g2 which is sprung over its free end. For conveniently forming the key-' way d2 the inner periphery of the bearing I-p-referably has a groove 2' having the shape of the inner portion of the keyway d2, the outer portion of which is out in the edge of the hearing I and engages the key at this edge, to prevent rotation of the shaft within the bearing.

To axially position the conical interceptor face 0 relatively to the dust guard N while permitting its crushing roll to oscillate in a direction radially of the ring B, I preferably make the bearing I with a spherical periphery c, which is oscilla.

torily and axially resistantly fitted in a spherical socket I in the bearing member J, so that it is free-to oscillate therein in said direction, but will axially position the: interceptor face relatively tothe dust guard during such oscillation, and

in the construction shown I make the bearing I as a ball bearing, having an inner race y, and an outer race a, rotatably connected by antifrictional balls or members 132. The inner race is fixed to the shaft H, and the outer race has a spherical peripherywhich is oscillatory in the socket The outer race has radial sockets or oil ducts k, and its periphery is encircled by an oil groove 7' connecting these ducts and in communication with an oil supply and in the construction shown I provide for resisting rotation of the outer race u, While permitting its oscillation in said direction, by providing it with a U shaped lock M, which is fitted within the peripheral groove 7" and has projections '12 extended radially inwardly and outwardly thereof at right angles to its direction of oscillation,

" which projections engage its radial recesses 7c,

andproject into reciprocal recesses 9'2 in the bearing member J, and thereby resist rotation of the outer race u while permitting its free oscillation in said direction. With this non-rotative connection between the outer race a and the bearing member J the outer race does not have to be tightly clamped within the bearing member, and its distortion thereby is avoided.

In operation, each plate 2 can be moved circumferentially of its shaft H for varying the relation of its shaft hole circumferentially of the latter, and for circumferentially varying the relation of the contactive surfaces of the plate to the adjacent surface of the wall at, for distributing wear of the plate over circumferentially successive portions of the latter, and each plate a will beautomatically so moved during and in response to radial movement of its shaft I-I; engagement of the teeth 0' in the apertures of the track 11 will resist rotation of a plate .2 with revolution of its shaft H, and will cause the plate to roll on the track during radial movement of said shaft, so that movement of the face of the plate 2 in contact with the adjacent wall a: will extend circumferentially of its shaft H as it moves radially with the latter, for distributing wear of the plate over circumferentially successive portions thereof, and for rollably dislodging particles from between the contactive faces of the plate and the Wall and rollably resisting leakage past the plate during. said radial movement; the plates 2 will exp-ansively resist leakage of dust into and out of the dust chamber w; the cup washers n will e-xpansively resist leakage along the shaft during its oscillation; the lock M will permit oscillation of the bearing I while resisting rotation of its outer member, and, the concave-convex key f2 will position the conical interceptor wall relatively to the dust guard by axially resistantly in both directions fixing its shaft H to its bearing I.

It will be understood that my invention is not limited to-the particular details of construction or combination and use, nor to the combination of features, set forth and shown as constituting its preferred form, since it can be availed of according to such modifications to any of these as circumstances or the judgment of those skilled in the art may dictate Without departing from the spirit of the invention.

What I claim is:

l. A sealing means for the shaft opening for a radially movable shaft, of the type having inner and outer axially spaced walls across and closing said opening and having clearance apertures around said shaft, and enclosing an axially extended annular chamber around said shaft; the combination therewith of a pair of axially spaced and expansively connected radially slidable inner and outer plates within said chamber and around and radially movable with said shaft and resisting leakage around the latter, and axially expansive U-shaped springs in operative relation to and connecting said plates, connected at their ends to said plates respectively, and constructed and arranged to axially expansively press said plates from each other and toward and into radially slidable contactive engagement with said walls respectively.

2. A sealing means for the shaft opening for a radially movable shaft, comprising a pair of axially spaced and axially expansively connected radially slidable inner and outer plates adapted to encircle and be carried and moved by said shaft, for resisting leakage around the latter, and expansive means in operative relation to and constructed to press said plates axially from one another, in combination with a pair of axial- 1y separable cover members removably mounted plates, for axially confining said plates between said walls,and one of said members being axially separably removable from the other and from said plates, for axially exposing the latter, and

for permitting axial removal thereof without molestation of the other of said members.

3. A sealing means for an opening for a rotary and radially and axially movable shaft, of the type having a rotary collar around and, rotatable with and resisting leakage around said shaft, and radially slidable plates, one at each side of and in axially spaced relation to said collar and around and carried and radially moved by said shaft and resisting leakage at the sides of said collar; the combination therewith of axially separable cover members removably mounted across and closing said opening, axially spaced from said collar and around and enclosing between them a chamber around said collar and said plates and in which the latter are radially slidably movable, one of said members having a wall across and closing said opening at one side of said plates and partitioning the latter from said opening, and the other of said members having a wall across and closing said chamber at the opposite side of the other of said plates, and enclosing the latter, said walls axially spaced from said collar and in slidable contactive engagement with said plates respectively, and permitting rotation of said collar without molestation from said plates, and resisting leakage past the latter, and axially expansive means betweeen and in operative relation to said plates and expansively pressing them from said collar and into contact with said walls respectively, said means being disposed around and a clearance distance from the periphery of said collar and permitting rotation of the latter without molestation from said expansive means.

4. A sealing means, for a shaft opening for a revoluble and radially movable shaft having means by which it is revolved and radially moved, of the type having a cover having a wall across and closing said opening and having a clearance aperture around said shaft; the combination therewith of a movable and slidable plate around and movable circumferentially of said shaft, and slidable with and in response to radial movement of said shaft, and resisting leakage around said shaft, at the side of and in slidable contactive engagement with said wall and across and closing said aperture, andhaving a provision moving said plate circumferentially of said shaft and by which said plate is moved circumferentially of the latter, and support means supporting said parts. i

5. A sealing means, for a shaft opening for a revoluble shaft having means by which it is revolved, of the type having a cover having a wall across and closing said opening and having a clearance aperture around said shaft; the combination therewith of a movable plate around and movable circumferentially of and resisting leakage around said shaft, at the side of and in movable contact with said wall, and across and closing said aperture, and having a provision moving said plate circumferentially of and by which said plate is moved circumferentially of said shaft, enforcement means enforcing movement of said plate circumferentially of said shaft, in operative relation to and cooperable with and engaged by said provision, and constructed and arranged during said engagement to enforce movement of said plate circumferentially of said shaft, and support means supporting said parts.

'3. A sealing means, for a shaft opening for a revoluble shaft having means by which it is revolved, of the type having acover having a wall across and closing said opening and having a clearance aperture around said shaft; the combination therewith of a movable plate around and movable circumferentially of and resisting leakage around said shaft, at the side of and in movable contact with said wall and across and closing said aperture, and having a provision moving said plate circumferentially of and by which said plate is moved circumferentially of said shaft, rotation resistance means resisting rotation of said plate with revolution of said shaft,

in operative relation to and in rotation resistance engagement with said plate and by which rotation of said plate with revolution of said shaft is resisted, and support means supporting said parts.

7. A sealing means, for a shaft opening for a revoluble and radially movable shaft having means by which it is revolved and radially moved, of the type having a cover having a wall across and closing said opening, and having a clearance aperture around said shaft; the combination therewith of a movable and slidable plate around i and movable circumferentially of said shaft, and slidable with and in response to radial movement of said shaft, and resisting leakage around said shaft, at the side of and in movable and slidable contact with said wall and across and closing said aperture, having a provision moving said plate circumferentially of and by which saidplate is moved circumferentially of said shaft, and having an arcuate peripheral portion coaxial with said shaft positioning said plate radially of and by which said plate is positioned radially of said shaft during said radial movement of the latter, track means sustaining said plate relatively to said shaft, in operative relation to and rollably engaged by said arcuate portion, and through the latter rollably sustaining said plate co-axially of said shaft, and by which said plate is rollably sustained relatively to said shaft during said radial movement of the latter, and support means supporting said parts.

8. A sealing means, for a revoluble and radially swingable shaft having means by which it is revolved and is radially swung in an arc-shaped path, of the type having a cover having a wall across and closing said opening and having a clearance aperture around said shaft; the combination, therewith of a swingable slidable plate around and swingable with and resisting leakage around said shaft, at the side of and in swingable slidable contact with said wall and across and closing said aperture, and having a provision positioning said plate radially of and by which said plate is positioned radially of said shaft during said swingable movement of the latter, an arcuate track means sustaining said plate radially of and by which said plate is sustained radially of said shaft, co-axial with and extended in the direction of said path, in operative relation to and movably engaged by said provision during said swingable movement of said plate,

and by which said plate is sustained radially of said shaft during said swingable movement of said plate with said shaft in said path, and support means supporting said parts.

GEORGE HOLT FRASER. 

